Temporal changes in seabird assemblage structure and trait diversity in the Rapa Nui (Easter Island) multiple-use marine protected area

1. For Rapa Nui (Easter Island) and its largest islet, Motu Nui, the change of the species assemblage over time was analysed, and a trait-based approach to evaluate the potential losses in seabird function across the past centuries was applied. At a finer scale, the seasonal changes in seabird species composition in the current seabird assemblage was assessed to better understand the dynamics of the long-term inferred patterns.
2. For Rapa Nui, the composition of the seabird assemblage between the prehistorical, historical, and current time has changed significantly. The most critical change, probably associated with human colonization, was observed between prehistoric and current times. The current diminished number of nesting seabird species was probably the result of local extirpation without evidence of colonization by new species.
3. For Motu Nui, changes in species composition were also followed by changes in trait structure, which were smaller than observed in Rapa Nui. This is probably due to the presence of a relatively high number of related species (i.e. Procellariids) with high similarities in their foraging behaviour.
4. The nesting seabird assemblages in Rapa Nui and Motu Nui differ in exposure to risk; thus, conservation strategies applied to the islands should be planned on a fine spatial scale. For Rapa Nui, which is an urban wildlife area with several invasive species and a low number of remaining native seabird species, management should focus on fencing and pets control. For Motu Nui, management should instead focus on the establishment of quarantine and other biosecurity tools to avoid both the entry and proliferation of new invasive species.

     

Tracing trophic pathways through the marine ecosystem of Rapa Nui (Easter Island)

1. The structure of food webs provides important insight into biodiversity, organic matter (OM) pathways, and ecosystem functioning.
2. Stable isotope analysis (δ¹³C and δ¹⁵N) was used to characterize the trophic structure and the main OM pathways supporting food webs in the Rapa Nui coastal marine ecosystem.
3. The trophic position of consumers and isotopic niche metrics were estimated for different assemblages (i.e. mesozooplankton, emergent zooplankton, reef invertebrates, reef fishes, pelagic fishes, and seabirds). Furthermore, the relative importance of different OM sources (i.e. macroalgae, zooxanthellate corals, and particulate OM [POM]) was assessed for heterotrophic consumers using Bayesian mixing model (MixSIAR).
4. Results show a clear pattern of ¹³C and ¹⁵N enrichment from small-sized pelagic and benthic invertebrates, to reef and pelagic fishes, and seabirds. Most invertebrates were classified as primary consumers, reef fishes as secondary consumers and pelagic predators and seabirds as tertiary and quaternary consumers.
5. Isotopic niche metrics indicate a low trophic diversity for pelagic assemblages (mesozooplankton and pelagic fishes), in contrast to reef fauna (invertebrates and fishes), whose higher trophic diversity suggest the exploitation of a wider range of trophic resources. Overlapping of standard ellipses areas between reef invertebrates and reef fishes indicates that both assemblages could be sharing trophic resources.
6. Mixing models results indicate that POM is the main trophic pathway for mesozooplankton, macroalgae (Rhodophyta) for emergent zooplankton, and a mix of coral-derived OM and Rhodophyta for coral reef assemblages such as macrobenthos and reef invertebrates. In contrast, POM contribution was notably more important for some pelagic fishes and seabirds from upper trophic levels.
7. This study provides key elements for conservation efforts on coral reefs, management planning and full-implementation of the recently created Rapa Nui Multiple Use Marine Protected Area.

     

Engaging recreational scuba divers in marine citizen science: Differences according to popularity of the diving area

1. Characterizing the composition of divers visiting different diving areas could help to design marine citizen science (MCS) projects that support biodiversity monitoring and marine conservation.
2. Recreational scuba divers mostly prefer warm and clear waters with coral reefs, and based on the Duffus and Dearden’s wildlife tourism framework we hypothesized that a more popular diving area is visited mostly by generalist divers, whereas in a less popular diving area a higher proportion of specialist divers would be found.
3. Recreational scuba divers were surveyed in diving centres at two diving areas, Rapa Nui (more popular, with warm and clear coral-reef waters) and the Chilean mainland (less popular, with productive and temperate–cold waters), to determine their diving profile, visiting profile, marine species knowledge, and interest and participation in MCS.
4. Support for our hypothesis (generalist divers on Rapa Nui and specialist divers on the mainland) was weak, but recreational divers on Rapa Nui were mostly foreign visitors who come for single visits, whereas divers from the mainland were predominantly Chileans who return repeatedly to the diving area. In both diving areas the divers expressed a strong interest to be trained and to participate in MCS, but divers from Rapa Nui were interested in brief pre-dive inductions, whereas divers from the Chilean mainland preferred intensive training courses.
5. Based on these findings we recommend specific MCS strategies for divers in both types of areas, e.g. simple protocols in more popular diving areas, with short pre-dive briefings for divers, and medium or long-term programmes in areas where most divers are local with high return rates. In these latter conditions more extensive training will be useful, which allows divers to gain more experience and assume higher responsibilities within an MCS project.

     

Conservation of Rapa Nui waters strongly supported by publications in Aquatic Conservation

1. This paper describes how a series of papers published in Aquatic Conservation have had a clear impact on the conservation process run at Rapa Nui by the Chilean Government and the Rapanui community.
2. Exploratory expeditions set the scientific basis for the creation of Rapa Nui Multiple Use Marine Protected Area.
3. Past conservation initiatives lacked proper participative processes and were strongly resisted by the local communities.
4. Science transfer through capacity building was key for a local transformation towards embracing marine conservation objectives.
5. Publications showed the importance of participation, a good balance between political will and a local wish for protection of the sea, and the incorporation of a local worldview, for a successful conservation process.
6. Strong differences between the socio‐ecological systems in mainland Chile and that in Rapa Nui were recognized and helped to build a new conservation strategy for Rapa Nui between the Chilean Government and Rapanui community.
7. International experience exchanges also helped to develop the conservation process in Rapa Nui, and recent ecological studies will help future Marine Protected Area implementation.

     

Ontogenetic movements of juvenile blacktip reef sharks: evidence of dispersal and connectivity between coastal habitats and coral reefs

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Science,capacity building and conservation knowledge: The empowerment of the local community for marine conservation in Rapa Nui

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Contributions of marine infrastructures to marine planning and protected area networking

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Conservation hotspots of biodiversity and endemism for Indo‐Pacific coral reef fishes

• 1. Distribution patterns of 3919 species of Indo‐Pacific reef fishes were analysed using GIS mapping software for the purpose of conservation prioritization of extraordinary high concentrations (‘hotspots’) of diversity and endemism.
• 2. Megadiversity countries with more than 1000 coral reef species include Indonesia, Australia, Philippines, Papua New Guinea, Malaysia, Japan, Taiwan, Solomon Islands, Palau, Vanuatu, Fiji, New Caledonia, and the Federated States of Micronesia.
• 3. The richest area for reef fishes is the renowned Coral Triangle, which includes eastern Indonesia, Sabah (Malaysia), Philippines, Papua New Guinea, and the Solomon Islands. The highest concentration of species within this region extends from south‐eastern Indonesia to the central Philippines.
• 4. Occupying only 3% of the surface area of the tropical Indo‐west and central Pacific, the heart of the Coral Triangle contains 52% of its total species.
• 5. The top‐ranked areas based on percentage of endemism are Easter Island, Baja California, Hawaiian Islands, Galapagos Islands, Red Sea, Clipperton Island, Marquesas, Isla del Coco, Mascarene Islands, and Oman.
• 6. The highest concentration of endemics per unit area occurs at remote south‐eastern Polynesian and eastern Pacific islands including Clipperton, Isla del Coco, Easter, Rapa, and the Pitcairn Group.

Copyright © 2007 John Wiley & Sons, Ltd.     

Local and remote physical processes driving variability of the planktonic system in the Juan Fernández Archipelago: A multidisciplinary framework providing conservation insights

1. The Juan Fernandez Ridge, a vulnerable marine ecosystem located far off the coast of central Chile and formed by several seamounts, guyots and three islands (Robinson Crusoe, Santa Clara and Alejandro Selkirk), has recently been declared a Coastal Marine Protected Area of Multiple Uses with several National Parks embedded in it.
2. Recent studies have highlighted the influence of remote and local oceanographic structures on the hydrographic dynamics of this ridge. However, there is still a gap in understanding how they affect the structure and dynamics of the surrounding insular planktonic communities.
3. A hydroacoustic and oceanographic survey was conducted during the austral spring (October 2016), including hydrographic and zooplankton sampling around Robinson Crusoe Island. Oceanographic features were identified and tracked using satellite data (chlorophyll-a (Chl-a) and sea surface temperature) and modelling results.
4. Two events of Chl-a increase relative to a threshold (>0.45 mg m⁻³) were forced by different physical processes, both affecting the western side of Robinson Crusoe Island. In event A during the cruise period, Chl-a subsurface maxima were associated with the arrival of a coastal meander originating on the continental shelf off Chile (remote process); the zooplankton was dominated by copepods and salps, with an evident coastal–oceanic gradient. In event B, Chl-a maxima were linked to a local upwelling forced by the intensification of a localized SSW wind. No influence of remote eddies or local Von Kármán vortices on Chl-a distribution was observed.
5. These findings highlight the influence of remote and local physical processes on the structure of planktonic communities around Robinson Crusoe Island. Understanding the variability of these mechanisms and their effects at the base of the pelagic food web is critical in adopting an ecosystem-level approach.

     

Factors (type,colour, density,and shape) determining the removal of marine plastic debris by seabirds from the South Pacific Ocean: Is there a pattern?

1. While floating near the sea surface plastic debris interacts with a number of external factors, including many different organisms. Seabirds have the most extensive documented history of interactions with plastics, through ingestion, entanglement, and nest construction.
2. In the present study, eight seabird species from the South Pacific Ocean were used as a proxy to determine potential patterns of removal of marine plastic debris, and three hypotheses were tested in relation to their feeding habits and nesting areas.
3. Plastics from abiotic compartments (Chilean continental coast, South Pacific Gyre, and Rapa Nui beaches) and biotic compartments (surface-feeding seabirds, diving seabirds, and nesting areas) were compared, according to their type, colour, shape, and density.
4. Continental beaches had a relatively wide range of colours and shapes, with many non-buoyant plastics. Samples from the South Pacific Gyre (SPG) and Rapa Nui (Easter Island) beaches comprised mainly hard, rounded, buoyant, and white/grey plastics.
5. These results indicate that the composition of floating plastics from terrestrial sources changes during transport with oceanic currents, reducing the proportion of prey-like plastics present in the subtropical gyres.
6. The stomach contents of surface-feeding and diving seabirds were dominated by hard, white/grey, and round plastic items, similar to plastics from the SPG, suggesting non-selective (accidental or secondary) ingestion.
7. Nesting areas had a more variable composition of brightly coloured plastics, suggesting a pattern of selective removal of plastics by seabirds, probably from oceanic sources.
8. The present study reveals extensive interactions of seabirds with plastics on a broader scale, which is highly relevant given that the impacts of plastics on seabirds are increasing worldwide, compromising their efficient conservation.

     

Ascidian communities in Southern Belize—a problem in diversity and conservation

• 1 Ecotourism has begun to impact the coral barrier reef of Belize. Pelican Cays, near the southern end of the reef, is one of the least disturbed areas and is rich in ascidian species.
• 2 Both the lack of stress and spatial competition probably contribute to the ability of normally cryptic species to live in exposed conditions. Activities associated with the growth in ecotourism are a potential threat to these unusual communities.
• 3 It is recommended that a rationale for the protection and management of this environmentally important area be developed.

     

A spatio‐temporal long‐term assessment on the ecological response of reef communities in a Caribbean marine protected area

1. Coral reef biodiversity is rapidly decreasing as a result of the loss of coral cover, which modifies the structure and functioning of the ecosystem. Understanding how coral reef communities respond in space and over the long term is essential in order to implement management strategies and reduce the effects of biodiversity loss on coral reefs.
2. Fish, coral, and algae communities were used as indicators to evaluate changes in coral reef systems. The variation of these communities was studied in a marine protected area composed of three management zones in Cozumel Coral Reef National Park in Quintana Roo, Mexico, over a period of 11 years (2004–2014). The following parameters were monitored annually: (i) total fish density; (ii) fish trophic group densities; (iii) species richness and three fish diversity indices; (iv) relative scleractinian coral cover; and (v) relative macroalgae cover.
3. In the years in which coastal development, such as the construction of a marina, took place, an increase in the abundance of territorial herbivorous and planktivorous fish was observed. As the coral recovered, macrocarnivores and sessile benthic invertivores were re‐established, whereas scraper herbivores showed no changes in the period of study in any of the three management zones.
4. Coral cover recovery showed rapid phase‐shift reversal (phase‐shift, macroalgae dominance over coral) in the three zones. Even though the fish density and coral cover recovered, the diversity indices of each fish trophic group exhibited a reduction in the three management zones over time.

     

Variations in cryptic assemblages in coral-rubble interstices at a reef slope in Ishigaki Island,Japan

The interstices of coral rubble provide a good refuge for cryptic small crustaceans and molluscs, which are important prey items for reef fishes. In this study, we focused on the assemblage composition of cryptic mobile species along the depth gradient at an outer reef slope. Traps with coral rubble (22 × 18 × 6 cm) were set at three sites at different depths, and mobile animals that colonized the traps were sorted. In total, 117 species of larger animals (mainly Decapoda and Gastropoda) were recorded: 71 species at the 3 m point, 53 species at the 11 m point, and 37 species at the 22 m point. On average, 260.3 individuals were captured in the traps at 3 m, while 95.3 and 57.8 individuals were captured at 11 and 22 m, respectively. MDS ordination showed that assemblage composition differed among the three sites. The most abundant species at the 3 m was the galathean crab Galathea mauritiana, followed by the gastropod Diala albugo. At 11 and 22 m, the galathean crab Sadayoshia edwardsii was most abundant. Thus, at the reef slope, the benthic assemblage was most diverse at the shallow site, and specific communities occurred at the three sites.     

Biodiversity,ecology, fisheries,and use and trade of Tetraodontiformes fishes reveal their socio‐ecological significance along the tropical Brazilian continental shelf

1. Tetraodontiformes fishes play a critical role in benthic and demersal communities and are facing threats due to anthropogenic impacts and climate change. However, they are poorly studied worldwide. To improve knowledge on the socio‐ecological significance and conservation of Tetraodontiformes a review of literature addressing the diversity, ecology, use and trade, conservation, and main threats of Tetraodontiformes combined with a comprehensive in situ dataset from two broad‐range multidisciplinary oceanographic surveys performed along the Tropical Brazilian Continental Shelf was undertaken.
2. Twenty‐nine species were identified, being primarily found on coral reefs and algal ecosystems. At these habitats, tetraodontids present highly diversified trophic categories and might play an important role by balancing the marine food web
3. Coral reef ecosystems, especially those near to the shelf break, seem to be the most important areas of Tetraodontiformes fishes, concentrating the highest values of species richness, relative abundance and the uncommon and Near Threatened species.
4. Ninety per cent of species are commonly caught as bycatch, being also used in the ornamental trade (69%) and as food (52%), serving as an important source of income for artisanal local fisheries.
5. Tetraodontiformes are threatened by unregulated fisheries, overexploitation, bycatch, and habitat loss due to coral reef degradation and the potential effects of climate change. These factors are more broadly impacting global biodiversity, food security, and other related ecosystem functions upon which humans and many other organisms rely.
6. We recommend the following steps that could improve the conservation of Tetraodontiformes along the tropical Brazilian Continental shelf and elsewhere: (i) data collection of the commercial, incidental, ornamental and recreational catches; (ii) improvement of the current legislation directed at the marine ornamental harvesting; (iii) increase efforts focused on the education and conservation awareness in coastal tourism and communities; and, most important, (iv) creation of marine reserves networks in priority areas of conservation, protecting either the species and key habitats for its survival.

     

Shelf‐edge reefs as priority areas for conservation of reef fish diversity in the tropical Atlantic

• 1. Data from fishing surveys employing bottom long‐lines were analysed to characterize the diversity, assemblages and distribution patterns of demersal fish along the Brazilian outer shelf and upper slope, between latitudes 13°S and 22°S.
• 2. Non‐metric multi‐dimensional scaling (MDS) and cluster analysis indicate three distinct species assemblages separated primarily by depth (the 200 m isobath) and secondarily by latitude (19°S), suggesting a continual transition along the depth and latitudinal gradients in the study area. Species richness was negatively correlated with depth, but with no clear relationship with latitude.
• 3. Results suggest the existence of reef formations on the shelf‐edge zone (40–200 m) and slope down to 500 m depth off the eastern Brazilian coast. More than 75% of the catches recorded were reef fish species from the families Serranidae, Lutjanidae, Malacanthidae, Muraenidae, Sparidae, Balistidae, Carangidae, Haemulidae, Scorpaenidae and Priacanthidae.
• 4. The maximum depth of occurrence for 20 reef species was extended from limits previously recorded.
• 5. The findings reinforce the hypothesis of a faunal corridor for species associated with deep reef formations along the shelf‐edge zone (40–200 m), in the South American continental margin, connecting the south‐western Atlantic and the Caribbean provinces.
• 6. The shelf‐edge reefs support important multi‐species fisheries and harbour critical habitats for the life cycle of many reef fish species, including spawning aggregation sites that are extremely vulnerable to human pressures, such as intensive fishing, shipping and offshore oil and gas exploitation; all activities currently expanding off the Brazilian coast.
• 7. Results reveal the biological importance of deep shelf‐edge reefs as a critical ecological area. Despite their importance, shelf edge reefs are not currently included in any marine protected area network in the tropical south‐western Atlantic. There is now an urgent need to enhance knowledge, implement adequate management strategies and consider these deeper habitats as priority areas for conservation. Copyright © 2011 John Wiley & Sons, Ltd.

     

Coastal development threatens Datan area supporting greatest fish diversity at Taoyuan Algal Reef,northwestern Taiwan

1. Taoyuan Algal Reef is a biodiverse coralline algal reef in north-west Taiwan, that is currently threatened by coastal development and industrial waste runoff.
2. As the reef lies in an exposed area that is frequently disturbed by monsoons, it is difficult to survey using traditional methods. Knowledge of the reef is therefore limited, and has until recently, long been regarded as a barren environment.
3. However, recent studies have revealed that the reef is inhabited by a diverse array of organisms, particularly at Datan, where a natural gas receiving terminal is planned for construction. Due to challenging environmental conditions, otolith assemblage and soundscape analyses were used to supplement traditional sampling methods including clove oil, netting, and pole-and-line fishing in order to assess the diversity of the fish community at Taoyuan Algal Reef.
4. Several fish species that had not been recorded by previous surveys were observed. Fish diversity and the average size of commercially targeted species were greatest at Datan G2. Predatory reef fishes such as groupers (Serranidae) and snappers (Lutjanidae), as well as several small endangered scalloped hammerhead sharks Sphyrna lewini were recorded at G2, where otolith assemblage analysis also indicated increased predatory activity. However, fewer individuals and species were recorded from tidal pools across all sites compared to previous surveys, suggesting a loss of biodiversity.
5. If construction work resumes at Datan, it will be likely to have adverse consequences for the reef itself, the species that inhabit it, and by extension, the local fishermen that rely upon it. Halting additional coastal development, reducing industrial and domestic pollution, as well as improving the management of traditional fisheries is recommended to protect this unique reef ecosystem from further degradation.

     

Spatial and temporal diversity of fish captured by light traps in various habitats in coastal waters in the oldest marine protected area in Vietnam and its implications for conservation

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Artificial reefs as a reef restoration strategy in sediment‐affected environments: Insights from long‐term monitoring

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The awakening of invertebrates: The daily dynamics of fishes and mobile invertebrates at Rapa Nui's multiple use marine protected area

• 1. On shallow reefs, day-night activity patterns between fishes and invertebrates are presumed to reflect trade-offs between feeding and predation; however, quantitative data on daily community dynamics are scarce. Moreover, night surveys may contribute important information for biodiversity inventories or baselines that normally are not considered.
• 2. This study used standardized day–night visual surveys of fishes and mobile invertebrates on the same transect lines in Rapa Nui (Easter Island) and investigated how diel patterns vary between taxonomic and trophic groups.
• 3. Distinct differences between taxonomic groups were observed, with fishes being more abundant during the day (>twice), whilst invertebrate abundance and richness showed an opposite trend with higher numbers at night (>three times).
• 4. Analysis of trophic groups showed that herbivorous and planktivorous fishes were more abundant during the day. Carnivorous fishes did not show any trends. Top predators (Apex) were observed only at very low abundances. However, a replacement amongst carnivorous fish species between day and night was found, where labridae fishes were practically absent during nights.
• 5. Most of the mobile invertebrates remained concealed during the day, probably due to the influence of predation risk (labrid fishes). The results emphasize the need for consideration of nocturnally active invertebrates in biodiversity inventories or baselines of reefs, which focus heavily only on diurnal surveys.
• 6. Day–night reef surveys should be included in marine protected area planning and monitoring as this provides a better understanding of shallow benthic communities and helps inform proper management decisions.

     

Effects of depth and eutrophication on the zooxanthella clades of Stylophora pistillata from the Gulf of Eilat (Red Sea)

• 1. The symbiotic association between corals and zooxanthellae has been a major contributing factor in the success of reef‐building corals.
• 2. The diversity of zooxanthellae harboured in the hermatypic coral Stylophora pistillata in the Gulf of Eilat (Aqaba), northern Red Sea, was investigated on the basis of the length and sequence variation of the 18S small subunit ribosomal DNA. Of several clades found worldwide, only clades A and C were found to be associated with this coral species in the Gulf.
• 3. No correlation between the pink and brown colour morphs of the coral S. pistillata and the zooxanthella clade was found. Shallow‐water colonies (5 m) harbour clade A while deeper‐water colonies (17 m) harbour either clade A or C. This coral is a brooding species that associates with different zooxanthellae at different depths.
• 4. Eutrophication from fish farms did not affect clade identity associated with Stylophora.

Copyright © 2008 John Wiley & Sons, Ltd.